Effect of repeated eccentric demands placed on the lower limb musculature during simulated Rugby Union play
- Authors: Brown, Lisa Gill
- Date: 2010
- Subjects: Sports injuries , Muscles -- Wounds and injuries , Tendons -- Wounds and injuries , Muscles -- Examination , Rugby football injuries , Rugby Union football players
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5114 , http://hdl.handle.net/10962/d1005192 , Sports injuries , Muscles -- Wounds and injuries , Tendons -- Wounds and injuries , Muscles -- Examination , Rugby football injuries , Rugby Union football players
- Description: Epidemiological studies consistently report that muscular strains are a primary injury type in rugby union with the majority of the strains occurring to the quadricep and hamstring musculature. Recently it has been suggested that poor eccentric muscular strength is a precursor to hamstring and quadriceps strains during intermittent sports that require rapid acceleration and deceleration. Despite the high incidence of these muscle injuries in Rugby Union there has been little research into the possible mechanisms involved. Thus, the purpose of this study was to measure the physiological and perceptual responses during a simulated Rugby Union laboratory protocol and further, to identify changes in muscle recruitment patterns and muscle strength over time by comparing this protocol to a continuous, constant load protocol covering the same distance. The experimental condition (EXP) required university level players to perform 80 minutes of simulated rugby union play in a laboratory setting (on a walkway of 22m) which was compared to that of a control condition (CON) which involved subjects covering the same distance, at a constant speed of 4.2km.h-1 on a treadmill. Physiological, biophysical and perceptual responses were measured pre-, at half-time and post-protocol. Heart rate was significantly (p<0.01) greater as a result of EXP in comparison to the CON. Electromyography (EMG) of the vastus medialis was significantly (p<0.01) greater during the CON protocol. The EXP condition elicited higher iEMG activity in the hamstring musculature at all time intervals. In addition the iEMG of the semitendinosus decreased significantly (p<0.01) as a result of the EXP protocol. Peak eccentric knee extensors (EXT) (-13.19%) and flexors (FLEX) (-12.81%) torque decreased significantly during the experimental protocol. After passive half-time (236.67 + 56.27Nm (EXT) and 173.89 + 33.3NM (FLEX)) and at the end of the protocol (220.39 + 55.16Nm and 162.89 + 30.66Nm) reduced relative to pre protocol (253.89 + 54.54Nm and 186.83 + 33.3Nm). Peak eccentric knee extensors did not change during the control protocol. „Central‟ and ‟Local” Rating of Perceived Exertion values were significantly (P<0.01) greater during the EXP protocol with an increased incidence of hamstring discomfort and perceived pain (5 out of 10). The EXP protocol resulted in significantly (p<0.01) increased incidence of delayed onset muscle soreness (DOMS). In conclusion, a stop-start laboratory protocol elicited increased heart rate, negatively impacted on muscle activity of the hamstrings, decreased eccentric strength in the lower limb musculature, resulted in increased ratings of „Central‟ and „Local‟ exertion and increased pain perception and increased incidence of DOMS. Thus, a stop-start rugby specific laboratory protocol has a negative impact on performance. Due to the specificity of the protocol being designed to match the demands of competitive match play it is expected that these changes in heart rate, muscle activity and strength, particularly eccentric strength, will impact negativity on performance during rugby match play and increase the likelihood of injury
- Full Text:
- Date Issued: 2010
- Authors: Brown, Lisa Gill
- Date: 2010
- Subjects: Sports injuries , Muscles -- Wounds and injuries , Tendons -- Wounds and injuries , Muscles -- Examination , Rugby football injuries , Rugby Union football players
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5114 , http://hdl.handle.net/10962/d1005192 , Sports injuries , Muscles -- Wounds and injuries , Tendons -- Wounds and injuries , Muscles -- Examination , Rugby football injuries , Rugby Union football players
- Description: Epidemiological studies consistently report that muscular strains are a primary injury type in rugby union with the majority of the strains occurring to the quadricep and hamstring musculature. Recently it has been suggested that poor eccentric muscular strength is a precursor to hamstring and quadriceps strains during intermittent sports that require rapid acceleration and deceleration. Despite the high incidence of these muscle injuries in Rugby Union there has been little research into the possible mechanisms involved. Thus, the purpose of this study was to measure the physiological and perceptual responses during a simulated Rugby Union laboratory protocol and further, to identify changes in muscle recruitment patterns and muscle strength over time by comparing this protocol to a continuous, constant load protocol covering the same distance. The experimental condition (EXP) required university level players to perform 80 minutes of simulated rugby union play in a laboratory setting (on a walkway of 22m) which was compared to that of a control condition (CON) which involved subjects covering the same distance, at a constant speed of 4.2km.h-1 on a treadmill. Physiological, biophysical and perceptual responses were measured pre-, at half-time and post-protocol. Heart rate was significantly (p<0.01) greater as a result of EXP in comparison to the CON. Electromyography (EMG) of the vastus medialis was significantly (p<0.01) greater during the CON protocol. The EXP condition elicited higher iEMG activity in the hamstring musculature at all time intervals. In addition the iEMG of the semitendinosus decreased significantly (p<0.01) as a result of the EXP protocol. Peak eccentric knee extensors (EXT) (-13.19%) and flexors (FLEX) (-12.81%) torque decreased significantly during the experimental protocol. After passive half-time (236.67 + 56.27Nm (EXT) and 173.89 + 33.3NM (FLEX)) and at the end of the protocol (220.39 + 55.16Nm and 162.89 + 30.66Nm) reduced relative to pre protocol (253.89 + 54.54Nm and 186.83 + 33.3Nm). Peak eccentric knee extensors did not change during the control protocol. „Central‟ and ‟Local” Rating of Perceived Exertion values were significantly (P<0.01) greater during the EXP protocol with an increased incidence of hamstring discomfort and perceived pain (5 out of 10). The EXP protocol resulted in significantly (p<0.01) increased incidence of delayed onset muscle soreness (DOMS). In conclusion, a stop-start laboratory protocol elicited increased heart rate, negatively impacted on muscle activity of the hamstrings, decreased eccentric strength in the lower limb musculature, resulted in increased ratings of „Central‟ and „Local‟ exertion and increased pain perception and increased incidence of DOMS. Thus, a stop-start rugby specific laboratory protocol has a negative impact on performance. Due to the specificity of the protocol being designed to match the demands of competitive match play it is expected that these changes in heart rate, muscle activity and strength, particularly eccentric strength, will impact negativity on performance during rugby match play and increase the likelihood of injury
- Full Text:
- Date Issued: 2010
"Feeling foggy?": an investigation into the self-reported post-concussive symptoms in rugby union players at university level
- Authors: Boulind, Melissa
- Date: 2005
- Subjects: Brain damage , Brain -- Wounds and injuries -- Complications , Brain -- Wounds and injuries -- Psychology , Sports injuries -- Psychological aspects , Rugby football injuries , Rugby Union football players
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2938 , http://hdl.handle.net/10962/d1002447 , Brain damage , Brain -- Wounds and injuries -- Complications , Brain -- Wounds and injuries -- Psychology , Sports injuries -- Psychological aspects , Rugby football injuries , Rugby Union football players
- Description: A study was conducted on the self-reported symptoms of Mild Traumatic Brain Injury sustained in Rugby Union at the pre- and post-season stages. A full sample of 30 rugby players at Rhodes University was compared to 27 non-contact sport controls. A reduced sample of 20 rugby players and 9 control participants provided improved control for education and IQ and was compared. Measures included the WAIS-III Vocabulary and Picture Completion Sub-tests to estimate IQ level, the symptom checklist on a widely used computer-based program (ImPACT), and a paper and pencil self-report 31-Item Post-Concussion Symptom Questionnaire. Independent and Dependent T-Test comparisons were conducted on the full and reduced samples. The symptoms reported by the rugby group appeared to be more pronounced on both the ImPACT Symptom Scale and the 31-Item Post-Concussion Symptom Questionnaire when compared to the control group at both the pre-and post-season stages. It was concluded that the rugby players demonstrated evidence to support the hypothesis of having sustained more previous concussions and reporting more symptoms at the pre-season stage when compared to comtrol participants. No prevalent changes for either the rugby or control groups were seen in dependent comparisons from pre-to post-season.
- Full Text:
- Date Issued: 2005
- Authors: Boulind, Melissa
- Date: 2005
- Subjects: Brain damage , Brain -- Wounds and injuries -- Complications , Brain -- Wounds and injuries -- Psychology , Sports injuries -- Psychological aspects , Rugby football injuries , Rugby Union football players
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2938 , http://hdl.handle.net/10962/d1002447 , Brain damage , Brain -- Wounds and injuries -- Complications , Brain -- Wounds and injuries -- Psychology , Sports injuries -- Psychological aspects , Rugby football injuries , Rugby Union football players
- Description: A study was conducted on the self-reported symptoms of Mild Traumatic Brain Injury sustained in Rugby Union at the pre- and post-season stages. A full sample of 30 rugby players at Rhodes University was compared to 27 non-contact sport controls. A reduced sample of 20 rugby players and 9 control participants provided improved control for education and IQ and was compared. Measures included the WAIS-III Vocabulary and Picture Completion Sub-tests to estimate IQ level, the symptom checklist on a widely used computer-based program (ImPACT), and a paper and pencil self-report 31-Item Post-Concussion Symptom Questionnaire. Independent and Dependent T-Test comparisons were conducted on the full and reduced samples. The symptoms reported by the rugby group appeared to be more pronounced on both the ImPACT Symptom Scale and the 31-Item Post-Concussion Symptom Questionnaire when compared to the control group at both the pre-and post-season stages. It was concluded that the rugby players demonstrated evidence to support the hypothesis of having sustained more previous concussions and reporting more symptoms at the pre-season stage when compared to comtrol participants. No prevalent changes for either the rugby or control groups were seen in dependent comparisons from pre-to post-season.
- Full Text:
- Date Issued: 2005
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